Backpack



FIG. 1 is a front left perspective view of a backpack showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof; and,

FIG. 6 is a bottom view thereof.

The design as shown in FIGS. 1-6 includes multiple registered trademarks that are the property of Louis Vuitton Malletier. 

CLAIM The ornamental design for a backpack, as shown and described. 